JP6900159B2 - Image forming device - Google Patents

Description

The present invention relates to an image forming apparatus such as a copier, a printer, a facsimile apparatus, or a multifunction device having these functions, which uses an electrophotographic system or an electrostatic recording system.

In an image forming apparatus using an electrophotographic method or the like, it is necessary to remove the toner (transfer residual toner) remaining on the surface of the image carrier after transferring the toner image from the image carrier such as a photoconductor to the transferred object. is there. Therefore, a cleaning member arranged in contact with the image carrier is used. As the cleaning member, a cleaning blade (hereinafter, also simply referred to as "blade") formed of an elastic member such as polyurethane rubber is widely used.

The blade is usually arranged in contact with the image carrier so as to be in the counter direction with respect to the moving direction of the image carrier. Therefore, the frictional force between the image carrier and the blade may become excessive. If this frictional force becomes excessive, the edge of the blade may be chipped, or the edge of the blade may be turned upside down in the moving direction of the image carrier. Toner and external additive have the effect of maintaining the slipperiness between the blade and the image carrier, but when the amount of toner and external additive intervening in the contact area between the image carrier and the blade is reduced, the blade is chipped. And curl are likely to occur. If the blade is chipped or curled, the blade may reduce the ability of the blade to scrape toner from the image carrier, resulting in poor cleaning.

Therefore, a band-shaped toner image (hereinafter, also referred to as “toner band”) is formed on the image carrier during non-image formation, and the toner in this toner band is applied to the contact portion (blade nip) between the image carrier and the blade. A method of supplying is known (Patent Document 1). By supplying toner to the blade nip, the frictional force between the image carrier and the blade can be reduced by the toner or the external additive, and chipping or curling of the blade can be suppressed.

Japanese Unexamined Patent Publication No. 2007-328175

However, in the conventional method, the density of the toner band (weight of toner per unit area) and the length (width) of the image carrier of the toner band in the moving direction are made uniform in the longitudinal direction of the blade. It turned out that there are the following issues.

That is, the chipping or curling of the blade depends on the contact pressure of the blade with respect to the image carrier. When the contact pressure is relatively high, the frictional force between the blade and the image carrier increases, so that the degree of progress of chipping of the blade increases and the blade tends to curl. The contact pressure generally has a variation depending on the position in the longitudinal direction of the blade, that is, a pressure distribution in the longitudinal direction of the blade, due to reasons such as a blade contact method and variations in parts. Therefore, the blade may be chipped from the portion where the contact pressure is relatively high, the blade may be easily rolled up, and the life of the unit including the blade may be shortened due to the need to replace parts. ..

On the other hand, in the conventional method, a toner band having a uniform density and width is formed in the longitudinal direction of the blade. Therefore, there is a possibility that the amount of toner in the toner band will be insufficient in the portion where the contact pressure is relatively high, while the amount of toner in the toner band will be excessive in the portion where the contact pressure is relatively low, and wasteful toner will be used. Will be consumed.

Therefore, an object of the present invention is to reduce toner consumption while suppressing problems caused by excessive frictional force according to the distribution of contact pressure of the cleaning member with respect to the image carrier in the longitudinal direction of the cleaning member. It is to provide an image forming apparatus which can be planned.

The above object is achieved by the image forming apparatus according to the present invention. In summary, the present invention is a unit that can be detachably attached to the main body of the image forming apparatus in the image forming apparatus, and corresponds to the image carrier that supports the toner image and the image carrier in the cleaning unit. A cleaning blade that comes into contact and removes deposits on the image carrier as the image carrier moves, and the cleaning in a width direction orthogonal to the moving direction of the image carrier as measured in the unit assembly step. A unit including an information holding member that holds contact pressure information, which is information on the contact pressure of the cleaning blade on the image carrier in each of a plurality of regions of the blade, and transfer from the image carrier. Except for the transfer member that transfers the toner image to the body, the input unit into which the contact pressure information is input, and the period during which the toner image is formed on the image carrier for each predetermined number of image forming operations. During the period, it has an execution unit that executes a supply operation of supplying toner to the cleaning unit using the supply toner image formed on the image carrier, and the execution unit is input to the input unit. Based on the contact pressure information, the amount of toner supplied to the region where the contact pressure is the first contact pressure becomes the first supply amount, and the contact pressure is the first contact pressure. The amount of toner supplied to the region, which is the second contact pressure larger than the pressure, is supplied to each of the regions in the supply operation so that the amount of toner supplied to the region becomes a second supply amount larger than the first supply amount. It is an image forming apparatus characterized in that the amount of the toner to be supported is set.

According to the present invention, it is possible to reduce the toner consumption while suppressing the trouble caused by the excessive frictional force according to the distribution of the contact pressure of the cleaning member with respect to the image carrier in the longitudinal direction of the cleaning member. Can be done.

It is a schematic cross-sectional view of an image forming apparatus. It is a schematic cross-sectional view of a blade. It is a graph which shows the relationship between the blade pressure and the chipping amount of a blade. It is a graph which shows the relationship between the blade pressure and the chipping amount of a blade for each amount of toner of a toner band. It is a graph for demonstrating the degree of occurrence of chipping of a blade for each position in the longitudinal direction of a blade. It is a schematic diagram of the seal in which the pressure distribution information of a blade is described. It is a block diagram which shows the schematic control mode of an image forming apparatus. It is a schematic flowchart figure of the operation which forms a toner band. It is a schematic diagram of a toner band. It is a block diagram which shows the schematic control mode of another example of an image forming apparatus. It is a schematic cross-sectional view of another example of an image forming apparatus.

Hereinafter, the image forming apparatus according to the present invention will be described in more detail with reference to the drawings.

[Example 1]
1. 1. Overall Configuration and Operation of the Image Forming Device FIG. 1 is a schematic cross-sectional view of the image forming device 100 of the present embodiment. The image forming apparatus 100 of this embodiment is a laser printer to which a process cartridge 250 can be attached and detached, which forms an image by using an electrophotographic method.

The photosensitive drum 1, which is a rotatable drum-type electrophotographic photosensitive member (photoreceptor) as an image carrier that supports a toner image, is driven by a drive motor (not shown) as a driving means in the direction of arrow W1 in the drawing (not shown). It is rotationally driven at a predetermined peripheral speed (process speed) (clockwise). In this embodiment, the photosensitive drum 1 is a negatively charged organic photosensitive member. The surface of the rotating photosensitive drum 1 is uniformly charged to a predetermined potential having a predetermined polarity (negative electrode property in this embodiment) by a charging roller 2 as a charging means. The charging roller 2 is arranged in contact with the photosensitive drum 1, and rotates in accordance with the rotation of the photosensitive drum 1. During the charging step, a predetermined charging bias is applied to the charging roller 2 from a charging bias power supply (not shown).

The surface of the charged photosensitive drum 1 is exposed by an exposure apparatus 21 as an exposure means. In this embodiment, the exposure apparatus 21 is a semiconductor laser scanner, and is a laser beam modulated in response to an image signal transmitted from an external device (personal computer or the like) communicably connected to the image forming apparatus 100. Is output. The exposure apparatus 21 scans and exposes (image exposure) the surface of the photosensitive drum 1 through the exposure window 9 of the process cartridge 250. Then, the absolute value of the potential of the exposed portion on the surface of the photosensitive drum 1 becomes lower than the absolute value of the charging potential formed by the charging roller 2, so that an electrostatic latent image (electrostatic image) is formed on the photosensitive drum 1. ) Is formed.

The electrostatic latent image formed on the photosensitive drum 1 is developed (visualized) by a developing device 5 as a developing means using toner as a developing agent, and a toner image is formed on the photosensitive drum 1. In this embodiment, a jumping development method and a reverse development method are adopted as the development methods. That is, a development bias in which an AC component and a DC component are superimposed is applied to the development roller 7 as a development member from the development bias power supply (not shown). Then, the toner charged negatively by triboelectric charging at the contact point between the developer layer thickness regulating member 6 and the developing roller 7 adheres to the image portion (exposed portion) of the electrostatic latent image on the photosensitive drum 1.

The toner image formed on the photosensitive drum 1 is transferred to a recording material (recording medium, transfer material, sheet) P such as paper, which is a transfer body, by a transfer roller 22 as a transfer means. The transfer roller 22 is pressed by a pressing spring (not shown) in the direction of the center of rotation of the photosensitive drum 1 to form a transfer portion N in which the photosensitive drum 1 and the transfer roller 22 come into contact with each other. During the transfer step, the transfer roller 22 is transferred from a transfer bias power supply (not shown) to a DC voltage having a polarity opposite to the charging polarity (normal charging polarity) of the toner during development (positive electrode property in this embodiment). Bias is applied. The recording material P is loaded and stored in the storage cassette 60. By rotationally driving the pickup roller 61 and the feeding roller 62 at a predetermined control timing, the recording material P is separated from the storage cassette 60 one by one, fed, and transported to the registration roller 63. Then, the recording material P is supplied to the transfer unit N by the registration roller 63 at the same timing as the toner image on the photosensitive drum 1.

The recording material P to which the toner image is transferred is separated from the photosensitive drum 1 and conveyed to the fixing device 23 as a fixing means. The fixing device 23 fixes (melts and fixes) the toner image transferred to the recording material P to the recording material P by heat, pressure, or the like. The recording material P on which the toner image is fixed is discharged (output) by the discharge roller 64 to a discharge tray 65 provided outside the device main body 150 of the image forming apparatus 100.

On the other hand, the surface of the photosensitive drum 1 after the toner image is transferred to the recording material P is cleaned by the cleaning device 4 as a cleaning means. The cleaning device 4 has a cleaning unit 3 including a blade 3a as a cleaning member and a support member 3b formed of a sheet metal that supports the blade 3a. The cleaning device 4 uses the blade 3a to remove the toner (transfer residual toner) that could not be completely transferred from the photosensitive drum 1 to the recording material P from the surface of the rotating photosensitive drum 1 and collect it in the collection container 10. To do. The blade 3a has a predetermined length in a longitudinal direction substantially parallel to the rotation axis direction of the photosensitive drum 1 and a lateral direction substantially orthogonal to the longitudinal direction, and has a plate shape (blade shape) having a predetermined thickness. ) Is a member. The blade 3a is arranged in contact with the photosensitive drum 1 at a predetermined angle so as to be in the counter direction (the direction in which the free end faces the upstream side in the rotation direction of the photosensitive drum 1) with respect to the rotation direction of the photosensitive drum 1. ing. The blade 3a comes into contact with the photosensitive drum 1 in a predetermined range including the edge of the tip (free end) in the lateral direction. In this embodiment, the length of the blade 3a in the longitudinal direction is 340 mm, which is longer than the image forming region on the photosensitive drum 1 (the image forming region falls within the length range of the blade 3a in the longitudinal direction). The image forming region is a region in which a toner image can be formed in a direction substantially orthogonal to the moving direction of the surface of the photosensitive drum 1.

In this embodiment, the photosensitive drum 1, the charging roller 2 as a process means acting on the photosensitive drum 1, the developing device 5, and the cleaning device 4 are integrally removable from the device main body 150, the process cartridge 250. Consists of.

Further, in this embodiment, the operation of each part of the image forming apparatus 100 is controlled by the CPU 103 (FIG. 7) as a control unit provided in the apparatus main body 150. The CPU 103 comprehensively controls the operation of each unit of the image forming apparatus 100 according to a program stored in the main body storage unit 101 having a storage medium such as a ROM.

Here, the image forming apparatus 100 executes a series of operations (job, printing operation) of forming and outputting an image on a single or a plurality of recording materials P, which is started by one start instruction. The job generally includes an image forming step, a front rotation step, a paper-to-paper step when forming an image on a plurality of recording materials P, and a back rotation step. The image forming step is a period in which an electrostatic latent image of an image actually formed and output on the recording material P is formed, a toner image is formed, and a toner image is transferred. Say. More specifically, the timing at the time of image formation differs depending on the position where the electrostatic latent image is formed, the toner image is formed, and the toner image is transferred. The pre-rotation step is a period during which the preparatory operation before the image forming step is performed from the input of the start instruction to the actual start of forming the image. The inter-paper process is a period corresponding between the recording material P and the recording material P when image formation is continuously performed on the plurality of recording materials P (continuous image formation). The post-rotation step is a period during which the rearranging operation (preparation operation) is performed after the image forming step. The non-image forming period is a period other than the image forming period, and is a preparatory operation when the pre-rotation process, the inter-paper process, the post-rotation process, and when the image forming apparatus 100 is turned on or returned from the sleep state. This includes the time of the pre-multi-rotation process. The supply operation of supplying toner to the contact portion between the photosensitive drum 1 and the blade 3a, which will be described later, is executed at the time of non-image formation.

2. Blade Manufacturing Method Next, the blade 3a manufacturing method in this embodiment will be described with reference to FIG. FIG. 2 is a schematic cross-sectional view of the blade 3a in this embodiment.

In this embodiment, the blade 3a is arranged in the thickness direction of the edge layer 3a (1) including the edge that abuts on the photosensitive drum 1 and the edge layer 3a (1) on the opposite side of the photosensitive drum 1. It has a two-layer structure including a base layer 3a (2). Both the edge layer 3a (1) and the base layer 3a (2) are formed of a polyurethane resin produced by using a polyisocyanate compound and a polyfunctional active hydrogen compound.

As a method for molding the blade 3a formed of the polyurethane resin, the following method can be used. High molecular weight polyol, polyisocyanate, cross-linking agent, catalyst, etc. are mixed at once and cast into a mold for molding. At that time, the blade 3a made of polyurethane resin is formed directly on the support member 3b. Then, in order to accurately produce the contact portion with the photosensitive drum 1, the tip portion of the blade 3a formed of the polyurethane resin is cut. The blade 3a can also be fixed to the support member 3a by adhesion or the like.

Further, as a method of forming the edge layer 3a (1) and the base layer 3a (2), a method of continuously molding using a rotary molding drum having a groove formed on the outer periphery thereof (Japanese Patent Laid-Open No. 2007-30385). ) Can be used.

In this embodiment, the total thickness of the blade 3a is 2 mm. At this time, the thickness t of the edge layer 3a (1) is preferably 100 to 300 μm. Further, in this embodiment, the edge layer 3a (1) has a hardness (JISA) of 77 ° and a rebound resilience of 10%, and the base layer 3a (2) has a hardness (JISA) of 77 ° and a rebound resilience of 45%. Is.

By using a material having a low rebound resilience for the edge layer 3a (1), the effect of removing deposits on the photosensitive drum 1 in repeated use is improved. Adhesions adhere to the surface of the photosensitive drum 1 due to filming of an external additive contained in the toner, fusion due to melting of the toner, and the like. By using a material having a low rebound resilience for the edge layer 3a (1), the edge of the blade 3a is less likely to be deformed when it comes into contact with the deposit, so that the effect of removing the deposit is improved. On the other hand, by using a material having a high elastic modulus for the base layer 3a (2), the original elastic effect of the blade 3a can be exhibited. That is, a stable contact state can be maintained even when the contact state changes such as an increase in the frictional force on the surface of the photosensitive drum 1 due to repeated use, and abnormal noise such as chattering and squeaking of the blade 3a is generated. Can be reduced.

3. 3. Blade chipping Next, the relationship between the contact pressure of the blade 3a with respect to the photosensitive drum 1 (hereinafter, also referred to as “blade pressure”) and the degree of occurrence of edge chipping of the blade 3a will be described. Regarding the image forming apparatus 100 and its elements, the front side of the paper surface in FIG. 1 is referred to as the “front side” and the back side of the paper surface is referred to as the “back side”. It is assumed that the depth direction connecting the "front side" and the "back side" is substantially parallel to the rotation axis direction of the photosensitive drum 1.

The problem caused by the excessive frictional force between the photosensitive drum 1 and the blade 3a at the contact portion (blade nip) Q between the blade 3a and the photosensitive drum 1 is not limited to the chipping of the blade 3a. It also includes curling up and the generation of abnormal noise. However, here, the chipping of the blade 3a, which causes the occurrence of cleaning failure and leads to the replacement of the unit including the blade 3a, will be described. Since the degree of occurrence of defects other than the chipping of the blade 3a also correlates with the frictional force between the photosensitive drum 1 and the blade 3a, it correlates with the degree of occurrence of chipping of the blade 3a.

In order to investigate the degree of occurrence of chipping of the blade 3a, a durability test for repeatedly outputting an image was performed using a representative image forming apparatus 100 having the configuration of this example. This test was carried out by installing the image forming apparatus 100 in a high temperature and high humidity environment of 30 ° C. and 80% in order to promote chipping of the blade 3a. A so-called solid white image having a printing rate of 0% was used as the output image, and the condition was set so that the toner did not easily reach the blade nip Q. The number of images to be output was 100,000, and the edge of the blade 3a after the number of images was output was observed with an optical microscope to quantify the degree of occurrence of chipping of the blade 3a. The blade pressure is at three points in the longitudinal direction of the blade 3a, that is, at a position (“F”) 50 mm from the end on the front side of the center to the center in the longitudinal direction of the blade 3a, and from the end on the back side to the center. The measurement was performed at a position of 50 mm on the side (“R”) and at the center (“C”). Further, in order to confirm the dependence of the blade 3a on the chipping blade pressure, the total pressure of the blade pressure is changed by changing the load of the spring (not shown) that presses the blade 3a in the direction of contacting the photosensitive drum 1. The test was conducted after changing to the standard. As the spring, a spring A having a spring constant of 50 gf / cm and a spring B having a spring constant of 75 gf / cm were used. Table 1 shows the blade pressure when each of the spring A and the spring B is used.

The blade pressure was measured using a measuring jig. In this measuring jig, three columnar virtual drums corresponding to the photosensitive drum 1 are arranged in the longitudinal direction of the blade 3a at predetermined intervals. A load cell for measuring the applied weight is connected to each virtual drum. Then, the blade 3a in the assembly of the process cartridge 250 supported by the support is pressed against the virtual drum, and the load applied by the blade 3a is detected by the load cell. Thereby, the contact pressure of the blade 3a with respect to each virtual drum, that is, the blade pressure of each of the three regions of the front side, the center, and the back side of the blade nip Q in the longitudinal direction of the blade 3a can be measured. .. In this embodiment, as the blade pressure, a linear pressure (gf / cm) obtained by expressing the value of the load (gf) measured by the load cell as the pressure per unit length of the blade 3a is used. However, the value of the load measured by the load cell may be used as it is. Further, the degree of occurrence of chipping of the blade 3a was quantified by using the total of the size of the chipping (length in the major axis direction) as the chipping amount (μm).

From Table 1, it can be seen that the variation in the blade pressure distribution in the longitudinal direction of the blade 3a tends to be larger when the spring B is used than when the spring A is used. This is because the blade 3a is bent due to the large spring pressure, and this bending puts stress on the container holding the blade 3a, so that the blade pressure distribution in the longitudinal direction of the blade 3a is likely to be uneven. This is to become. Here, a durability test was conducted using a spring A and a spring B in order to investigate the dependence of the blade 3a on the blade pressure, but the spring B is used in the image forming apparatus 100 of this embodiment. ..

FIG. 3 shows the relationship between the blade pressure obtained by the durability test and the chipping amount of the blade 3a. From the figure, it can be seen that there is a proportional relationship between the blade pressure and the chipping amount of the blade 3a. This is because the higher the blade pressure, the greater the frictional force between the photosensitive drum 1 and the blade 3a, and the greater the amount of deformation of the edge of the blade 3a, which increases the stress on the blade 3a. ..

Next, the relationship between the amount of toner supplied and the amount of chipping of the blade 3a in the case of performing a supply operation of supplying toner to the blade nip Q in order to reduce the frictional force between the photosensitive drum 1 and the blade 3a will be described. To do.

As described above, a method of supplying toner to the blade nip Q is known in order to reduce the frictional force between the photosensitive drum 1 and the blade 3a in the blade nip Q. Specifically, at the time of non-image formation, a band-shaped toner image (toner band) long in the longitudinal direction of the blade 3a is formed on the photosensitive drum 1. Then, the toner in this toner band is supplied to the blade nip Q without being transferred to the recording material P. As a result, the toner in the toner band and its external additive intervene between the photosensitive drum 1 and the blade 3a and act as a lubricant, reducing the frictional force between the photosensitive drum 1 and the blade 3a, thereby reducing the blade. The stress applied to 3a can be relaxed.

In order to investigate the degree of chipping of the blade 3a when the toner band is formed, a representative image forming apparatus 100 having the configuration of this embodiment is used to repeatedly output an image and form the toner band at a predetermined frequency. A durability test was conducted. Here, once for every 100 image outputs, a toner band having a length of the blade 3a in the longitudinal direction of 340 mm (a length covering the entire length range of the blade 3a in the longitudinal direction) is formed, and the toner in this toner band is formed. Was supplied to the blade nip Q. The width of the toner band (the length of the photosensitive ram 1 in the rotation direction) was set to two levels of 10 mm and 20 mm. Further, when the toner band passes through the transfer unit N, the transfer bias applied to the transfer roller 22 is turned off. As a result, it is possible to suppress the transfer of the toner in the toner band to the transfer roller 22 and increase the amount of toner reaching the blade nip Q. The settings of the spring A and the spring B, the number of image outputs, the output image, the test environment, and the like are the same as those of the durability test obtained in FIG. Further, when the spring A and the spring B were used in this representative image forming apparatus 100, the blade pressure distribution in the longitudinal direction of the blade 3a was the same as that shown in Table 1.

FIG. 4 shows the relationship between the blade pressure for each width of the toner band and the chipping amount of the blade 3a obtained by the durability test for forming the toner band. From the figure, it can be seen that the larger the width of the toner band, the smaller the chipping amount of the blade 3a.

Based on the result of FIG. 4, FIG. 5 shows the relationship between the blade pressure distribution in the longitudinal direction of the blade 3a and the chipping amount of the blade 3a when the spring B is used (the configuration of this embodiment), and the width of the toner band. It is plotted for each. In this example, in order to enable the blade 3a to be used for a sufficiently long period of time, it is desirable that the chipping amount of the blade 3a in the durability test is 8 μm or less.

From FIG. 5, it can be seen that in order to enable the blade 3a to be used for a sufficiently long period of time, it is desirable to form a toner band having a width of 20 mm once for every 100 image outputs. This is to reduce the amount of chipping of the blade 3a on the front side and the center in the longitudinal direction of the blade 3a, which has a relatively high blade pressure, to 8 μm or less. However, for example, since the blade pressure is relatively low on the inner side of the blade 3a in the longitudinal direction, it can be seen that it is not necessary to form a toner band having a width of 20 mm once for every 100 image outputs.

4. Toner band control As described above, the degree of chipping of the blade 3a differs depending on the blade pressure (FIG. 3). Further, the amount of toner in the toner band required to be supplied in order to reduce the chipping of the blade 3a in each region differs depending on the blade pressure in each region of the blade nip Q in the longitudinal direction of the blade 3a (FIG. 4, FIG. FIG. 5).

Therefore, in this embodiment, the amount of toner supplied to each of the plurality of regions by the supply operation based on "pressure distribution information" including information on the blade pressure in the plurality of regions of the blade nip Q in the longitudinal direction of the blade 3a. To change. In this embodiment, by changing the size of a predetermined toner image (toner band, toner image for supply ) to reach each of the plurality of regions in the supply operation, the toner image is supplied to each of the plurality of regions by the supply operation. Change the amount of toner. In particular, in this embodiment, the length (width) of the photosensitive drum 1 of the toner image in the rotation direction is changed as the size of the predetermined toner image. As a result, wasteful consumption of toner can be suppressed, and the life of the blade 3a can be extended. Hereinafter, it will be described in more detail.

The blade pressure distribution in the longitudinal direction of the blade 3a can be measured when the process cartridge 250 is assembled at the factory. Therefore, it is suitable to mark the process cartridge 250 with pressure distribution information, which is information on the blade pressure distribution in the longitudinal direction of the blade 3a, during the assembly process. In this embodiment, in the process of assembling the process cartridge 250, the blade pressure in each region of the front side, the center, and the back side in which the blade nip Q in the longitudinal direction of the blade 3a is evenly divided into three is measured. Then, a sticker 11 (FIG. 1) in which pressure distribution information including information on the blade pressure in each region of the blade nip Q in the longitudinal direction of the measured blade 3a is described is attached to the process cartridge 250. In particular, in this embodiment, as the pressure distribution information, a region (front side, center, back side) of the blade nip Q in the longitudinal direction of the blade 3a is associated with a reference numeral indicating a value (range) of the blade pressure. The information is described on the seal 11. The seal 11 on which this pressure distribution information is described is attached to the process cartridge 250 before the process cartridge 250 is shipped (for example, following the measurement of the blade pressure in the assembly process). Here, the seal 11 is an example of a description unit in which the pressure distribution information of the process cartridge 250 is described. Further, this description unit is an example of an information holding means (information holding unit) that holds the pressure distribution information possessed by the process cartridge 250.

As described above, the blade pressure can be measured in a state where the photosensitive drum 1 is not incorporated in the process cartridge 250 (the blade 3a is incorporated). As described above, the blade pressure may vary depending on the position of the blade 3a in the longitudinal direction. This variation may occur due to variations in the material and dimensions of the blade 3a for the blade 3a alone, or variations in the mounting position and mounting conditions of the blade 3a during manufacturing. Further, for the same reason as described above, the blade pressure may vary depending on, for example, each process cartridge 250 (blade 3a) or each production lot of the process cartridge 250 (blade 3a). Therefore, the blade pressure can be measured for each unit in which the blade pressure may vary, which affects the degree of occurrence of chipping of the blade 3a. For example, each process cartridge 250 (blade 3a), each production lot of the process cartridge 250 (blade 3a), and the like. When measuring for each production lot, the blade pressure can be measured using the representative components of the process cartridge 250. When a representative component is used, the blade pressure measured by one set of components may be used, or the average value of the blade pressure measured by a plurality of sets of components may be used. In this embodiment, the blade pressure is measured for each process cartridge 250 (blade 3a). Further, in this embodiment, the blade nip Q is divided into three in the longitudinal direction of the blade 3a, and the blade pressure measured at a predetermined position in each region is defined as the blade pressure in each region, but the present invention is not limited to this. The number of divisions may be increased or decreased as compared with this embodiment. The larger the number of divisions, the higher the accuracy of extending the life of the blade 3a while suppressing wasteful toner consumption. However, if the number of divisions is too large, the operation becomes complicated and the control becomes complicated. May bring. Typically, the number of divisions is preferably about 3 to 10. The average value, representative value (maximum value, etc.), total, and the like of the blade pressures measured at a plurality of points in each region of the blade nip Q in the longitudinal direction of the blade 3a may be used as the blade pressure in each region.

FIG. 6 is a schematic view showing an example of a sticker 11 attached to the process cartridge 250. The "A", "B", and "C" in the "Address" column described on the seal 11 are the front side F, the center C, and the back side R of the blade nip Q in the longitudinal direction of the blade 3a, respectively. Corresponds to each area. Further, "1", "2", and "3" in the "Value" column described on the seal 11 correspond to the following blade pressure ranges, respectively. That is, "1" corresponds to a blade pressure in the range of 20 gf / cm or more and less than 25 gf / cm. Further, "2" corresponds to a blade pressure in the range of 25 gf / cm or more and less than 30 gf / cm. Further, "3" corresponds to a blade pressure in the range of 30 gf / cm or more and less than 35 gf / cm.

It is described on the sticker 11 attached to the process cartridge 250 newly attached to the device main body 150 when an operator such as a user or a service person replaces the process cartridge 250 with respect to the device main body 150. Read pressure distribution information. Further, the operator inputs the read pressure distribution information to the device main body 150 (input unit) . For example, when the process cartridge 250 reaches the end of its life at the user's site, the service person receives a report and goes to the user's site to replace the process cartridge 250. At that time, the service person reads the pressure distribution information written on the seal 11 and inputs it to the apparatus main body 150. Then, on the device main body 150 side, a process for controlling the size (width in this embodiment) of the toner band to reach each region of the blade nip Q in the longitudinal direction of the blade 3a according to the input pressure distribution information. Is done.

FIG. 7 is a block diagram showing a schematic control mode of the image forming apparatus 100 of this embodiment. As described above, the device main body 150 is provided with the CPU 103 as a control unit and the main body storage unit 101 connected to the CPU 103. Further, the CPU 101 is connected to an exposure control unit 102, which is a control circuit of the exposure device 21, and an environment sensor 104 as an environment detection means for detecting at least one of the temperature and humidity inside or outside the device body 150. ing. In this embodiment, the environment sensor 104 detects the temperature and humidity of the environment in which the image forming apparatus 100 is installed (the environment outside the apparatus main body 150), and transmits the information to the CPU 103. Further, the CPU 103 is connected to a drive control unit 105, which is a control circuit for the drive motor of the photosensitive drum 1, and a high-voltage power supply 106 such as a charging power supply and a transfer power supply. Further, the CPU 103 is connected to an operation display unit 107 such as a touch panel, which has the functions of an input means for inputting information to the CPU 103 and a display means for displaying information under the control of the CPU 103.

The pressure distribution information written on the sticker 11 attached to the process cartridge 150 is input from the operation display unit 107. The CPU 103 stores the input pressure distribution information in the main body storage unit 101.

Then, in this embodiment, the CPU 103 (execution unit) forms a toner band on the photosensitive drum 1 and supplies the toner to the blade nip Q at a predetermined timing at the time of non-image formation for every 100 image output sheets. Perform the supply operation. That is, in this embodiment, the CPU 103 functions as a counting means, and each time an image is output, the number of image outputs is integrated and stored in the main body storage unit 101. The CPU 103 recognizes that the execution timing of the supply operation has arrived when the integrated number of image outputs reaches the threshold value of 100 images. Further, in the present embodiment, the CPU 103 executes the supply operation in the case of a high temperature and high humidity environment in which the blade 3a is likely to be chipped. Then, the CPU 103 controls the width of the toner band to reach each region of the blade nip Q in the longitudinal direction of the blade 3a based on the pressure distribution information input from the operation display unit 107 and stored in the main body storage unit 101. .. The CPU 103 turns off the transfer bias applied to the transfer roller 22 when the toner band passes through the transfer unit N. At this time, a voltage having the same polarity as the normal charging polarity of the toner may be applied to the transfer roller 22.

FIG. 8 is a schematic flowchart of the control for executing the supply operation in this embodiment. Here, it is assumed that the supply operation is executed during the paper-to-paper process of the job. Every time one image is output, the CPU 103 reads the number of image output sheets accumulated and stored in the main body storage unit 101 (S101), and determines whether or not the number of image output sheets has reached 100 (S102). ). When it is determined in S102 that the number of sheets has reached 100, the CPU 103 reads the temperature / humidity information of the environment detected by the environment sensor 104 (S103), and is it a high temperature (25 ° C. or higher) / high humidity environment (60% or higher)? It is determined whether or not (S104). When it is determined in S104 that the environment is high temperature and high humidity, the CPU 103 reads the pressure distribution information stored in the main body storage unit 101 (S105). Then, the CPU 103 determines the toner band to reach each region of the blade nip Q in the longitudinal direction of the blade 3a based on the preset information indicating the relationship between the blade pressure and the width of the toner band as shown in Table 2. The width is determined (S106). In this embodiment, the information showing the relationship as shown in Table 2 is stored in advance in the main body storage unit 101.

As shown in Table 2, in this embodiment, when the blade pressure (“Value” described on the seal 11) is “1”, no toner band is formed (the width of the toner band is 0 mm). When the blade pressure is "2", the width of the toner band is set to 10 mm. When the blade pressure is "3", the width of the toner band is set to 20 mm. In this embodiment, the density of the toner band (weight of toner per unit area) is constant at a predetermined density (predetermined halftone or solid density (maximum density level)) regardless of the value of the blade pressure. Has been done.

Then, the CPU 103 controls the exposure control unit 102, the high-voltage power supply 106, and the drive control unit 105 to form a toner band on the photosensitive drum 1, and supplies the toner to the blade nip Q (S107). As shown in FIG. 9, the toner band has a width determined by S106 for each portion of the blade 3a supplied to each region of the blade nip Q in the longitudinal direction. FIG. 9 schematically shows a toner band in the case where the pressure distribution information described on the seal 11 is the example shown in FIG. After that, the CPU 103 resets the number of image output sheets stored in the main body storage unit 101 to 0 (S108).

As described above, in the present embodiment, the CPU 103 changes the size of the toner band to reach each region according to the blade pressure of each region of the blade nip Q in the longitudinal direction of the blade 3a, thereby changing each region. Change the amount of toner in the toner band supplied to. At this time, the CPU 103 determines that the amount of toner in the region where the blade pressure is the first contact pressure is smaller than the amount of toner in the region where the blade pressure is the first contact pressure. Reduce. That is, in this embodiment, in the region where the blade pressure is the second contact pressure smaller than the first contact pressure than the size of the toner image to reach the region where the blade pressure is the first contact pressure. Make the size of the toner image to be reached smaller. In this embodiment, the width of the toner band (the length in the rotation direction of the photosensitive drum 1) is changed as the size of the toner band, but the size is not limited to this. Since the toner in the toner band moves (spreads) to some extent in the longitudinal direction of the blade 3a when it is scraped off by the blade 3a, the length of the blade 3a in the toner band in the longitudinal direction may be changed. Further, both the width of the toner band and the length of the blade 3a in the longitudinal direction may be changed. Further, the toner band may be divided into a plurality of layers at least in the width direction or the longitudinal direction of the blade 3a, and the total length of the toner bands in the divided direction may be changed.

The pressure distribution information stored in the main body storage unit 101 is reset every time the process cartridge 250 is replaced. Further, when the pressure distribution information is not stored in the main body storage unit 101 for some reason, the CPU 103 assumes that the blade pressure is "3" in all of the blade nip Qs in the longitudinal direction of the blade 3a, for example, and the width of the toner band. Can be controlled.

As described above, according to the present embodiment, by adjusting the width of the toner band according to the blade pressure distribution in the longitudinal direction of the blade 3a, the chipping amount of the blade 3a is suppressed substantially uniformly in the longitudinal direction of the blade 3a. At the same time, it becomes possible to reduce the amount of toner consumed.

[Example 2]
Next, other examples of the present invention will be described. The basic configuration and operation of the image forming apparatus of this embodiment are the same as those of the first embodiment. Therefore, in the image forming apparatus of this embodiment, elements having the same or corresponding functions or configurations as those of the first embodiment are designated by the same reference numerals, and detailed description thereof will be omitted.

In Example 1, the amount of toner in the toner band supplied to each region was changed by changing the size of the toner band reaching each region of the blade nip Q in the longitudinal direction of the blade 3a. On the other hand, in this embodiment, the toner band supplied to each area by changing the concentration of the toner band (weight of toner per unit area) reaching each area of the blade nip Q in the longitudinal direction of the blade 3a. Change the amount of toner in.

In this embodiment, in S106 of FIG. 8, the CPU 103 has a blade nip Q in the longitudinal direction of the blade 3a based on preset information indicating the relationship between the blade pressure and the density of the toner band as shown in Table 3. Determine the density of the toner band to reach each region of. In this embodiment, the information indicating the relationship as shown in Table 3 is stored in advance in the main body storage unit 101.

As shown in Table 3, in this embodiment, when the blade pressure (“Value” described on the seal 11) is “1”, no toner band is formed (the concentration of the toner band is 0 mg / cm ² ). When the blade pressure is "2", the concentration of the toner band is set to a predetermined X (> 0) mg / cm ² (for example, 0.3 mg / cm ² ). When the blade pressure is "3", the concentration of the toner band is set to a predetermined Y (> X) mg / cm ² (for example, 0.5 mg / cm ² ). The density of the toner band can be controlled by controlling the exposure amount by the exposure apparatus 3. Here, the density of the toner band is represented by the amount of toner loaded, but it may be information on the density level that specifies the exposure amount of the exposure apparatus 3.

As described above, in the present embodiment, the CPU 103 changes the density of the toner band to reach each region according to the blade pressure of each region of the blade nip Q in the longitudinal direction of the blade 3a, thereby changing each region. Change the amount of toner in the toner band supplied to. At this time, the CPU 103 makes the concentration of the region where the blade pressure is the first contact pressure smaller than the concentration of the region where the blade pressure is the first contact pressure smaller than the concentration of the region where the blade pressure is the first contact pressure. ..

As described above, according to the present embodiment, by adjusting the density of the toner band according to the blade pressure distribution in the longitudinal direction, the chipping amount of the blade 3a can be suppressed substantially uniformly in the longitudinal direction of the blade 3a. At the same time, it becomes possible to reduce the amount of toner consumed.

[Example 3]
Next, other examples of the present invention will be described. The basic configuration and operation of the image forming apparatus of this embodiment are the same as those of the first embodiment. Therefore, in the image forming apparatus of this embodiment, elements having the same or corresponding functions or configurations as those of the first embodiment are designated by the same reference numerals, and detailed description thereof will be omitted.

In Examples 1 and 2, the supply operation was executed at a predetermined execution frequency, and the width and density of the toner band to reach each region of the blade nip Q in the longitudinal direction of the blade 3a were adjusted in each supply operation. On the other hand, in this embodiment, the amount of toner supplied to each region is changed by changing the frequency of forming the toner band that reaches each region of the blade nip Q in the longitudinal direction of the blade 3a.

That is, the toner and its external additive intervening in the blade nip Q decrease as the traveling distance (rotation speed) of the photosensitive drum 1 increases, and the blade 3a is likely to be chipped. Therefore, when the blade pressure is relatively high and the blade 3a is relatively likely to be chipped, it is desired to supply toner to the blade nip Q with a higher frequency. On the other hand, when the blade pressure is relatively low and the blade 3a is relatively unlikely to be chipped, the toner consumption is reduced by relatively reducing the frequency of supplying toner to the blade nip Q. Can be done.

In this embodiment, the CPU 103 counts the number of image output sheets for determining the formation timing of each toner band reaching each region of the blade nip Q in the longitudinal direction of the blade 3a and stores the image output number in the main body storage unit 101. .. Further, the CPU 103 compares the integrated number of image outputs for each region with the threshold value set according to the blade pressure in each region, and determines whether or not the timing for forming the toner band has arrived. .. Then, when the toner band is formed, the number of image output sheets accumulated for that region is reset to 0.

The CPU 103 determines the toner band to reach each region of the blade nip Q in the longitudinal direction of the blade 3a based on the preset information indicating the relationship between the blade pressure and the frequency of forming the toner band as shown in Table 4. Judge the formation timing. In this embodiment, the information showing the relationship as shown in Table 4 is stored in advance in the main body storage unit 101.

As shown in Table 4, in this embodiment, when the blade pressure (“Value” described on the seal 11) is “1”, no toner band is formed. When the blade pressure is "2", a toner band is formed for every 200 image outputs. When the blade pressure is "3", a toner band is formed for every 100 image output sheets. In this embodiment, the width of the toner band is 20 mm and the concentration is constant at a predetermined concentration of Ymg / cm ² regardless of the value of the blade pressure.

As described above, in the present embodiment, the CPU 103 changes the frequency of forming the toner band to reach each region according to the blade pressure of each region of the blade nip Q in the longitudinal direction of the blade 3a. Change the amount of toner supplied to each area. At this time, the CPU 103 makes the frequency of the region where the blade pressure is the first contact pressure lower than the frequency of the region where the blade pressure is the first contact pressure lower than the frequency of the region where the blade pressure is the first contact pressure. ..

As described above, according to the present embodiment, by adjusting the formation frequency of the toner band according to the blade pressure distribution in the longitudinal direction of the blade 3a, the chipping amount of the blade 3a is substantially uniform in the longitudinal direction of the blade 3a. At the same time, it becomes possible to suppress the consumption of toner.

[Example 4]
Next, other examples of the present invention will be described. The basic configuration and operation of the image forming apparatus of this embodiment are the same as those of the first embodiment. Therefore, in the image forming apparatus of this embodiment, elements having the same or corresponding functions or configurations as those of the first embodiment are designated by the same reference numerals, and detailed description thereof will be omitted.

In Examples 1 to 3, the pressure distribution information was described on the sticker 11 attached to the process cartridge 250. On the other hand, in this embodiment, the pressure distribution information is stored in the IC tag 109 (FIG. 10) attached to the process cartridge 250. Here, the IC tag 109 is an example of a storage medium in which the pressure distribution information of the process cartridge 250 is stored. Further, this storage medium is an example of an information holding means that holds the pressure distribution information possessed by the process cartridge 250.

When the pressure distribution information is held in the seal 11 as in the first to third embodiments, the operator manually inputs the process cartridge 250 when the process cartridge 250 is replaced, so that the input may be mistaken. Therefore, in this embodiment, the pressure distribution information is input to the IC tag 109 during the assembly process of the process cartridge 250 and stored.

FIG. 10 is a block diagram showing a schematic control mode of the image forming apparatus 100 of this embodiment. The IC tag 109 is a memory tag having a non-volatile memory, and is attached to the process cartridge 250. On the other hand, the apparatus main body 150 is provided with an IC tag reading unit 108 that reads the information stored in the IC tag 109 and inputs it to the CPU 103. When the process cartridge 250 is attached to the apparatus main body 150, the IC tag 109 is connected to the IC tag reading unit 108. As a result, the pressure distribution information stored in the IC tag 109 is input to the CPU 103 (input unit) by the IC tag reading unit 108. Then, the CPU 103 can control the operation of forming the toner band in the same manner as in Examples 1 to 3 based on the information input by the IC tag reading unit 108. The pressure distribution information read from the IC tag 109 may be temporarily stored in the main body storage unit 101 for use.

As described above, according to the present embodiment, the same effects as those of the first to third embodiments can be obtained, and the operation of forming the toner band can be appropriately controlled by preventing mistakes when inputting the pressure distribution information. Can be facilitated.

[Other]
Although the present invention has been described above with reference to specific examples, the present invention is not limited to the above-mentioned examples.

The methods for changing the amount of toner supplied to each region of the blade nip in the longitudinal direction of the blade described in Examples 1 to 3 can be used in any combination. That is, the amount of toner supplied to each region can be changed by changing two or more of the size, density, and formation frequency of the toner band.

In Examples 1 to 3, the pressure distribution information is described on a sticker attached to the process cartridge (that is, a description portion provided on the process cartridge itself), but the pressure distribution information is not limited thereto. The provider of the process cartridge can present the pressure distribution information to the operator by any means for each individual process cartridge (blade), each production lot, and the like. For example, it can be presented in articles distributed with the process cartridge such as packaging of the process cartridge or an instruction manual, or can be presented on the process cartridge on the network or the homepage of the provider of the image forming apparatus.

Further, in Examples 1 to 3, the operator inputs the pressure distribution information, but the operator inputs, for example, the individual identification number of the process cartridge as long as the information can identify the pressure distribution information in the process cartridge. Or lot number. For example, a control unit provided in the main body of the device may be connected to the network by a network connection unit. In this case, for example, the pressure distribution information may be associated with the individual identification number or lot number of the process cartridge and stored in an external storage unit such as a service base of the process cartridge or the provider of the image forming apparatus. The external storage unit and the control unit provided in the main body of the device are connected to the network via the network connection unit. The operator inputs the individual identification number and lot number of the process cartridge to be mounted on the device main body from the operation unit provided on the device main body to the control unit. The individual identification number or lot number of the process cartridge can be presented in the process cartridge itself or in the goods distributed with the process cartridge such as the process cartridge packaging and instructions. Then, the control unit can obtain the pressure distribution information corresponding to the input individual identification number and lot number of the process cartridge from the external storage unit.

Further, in Example 4, it has been described that the pressure distribution information is stored in the storage medium provided in the process cartridge. When the storage medium is provided in the process cartridge in this way, the information showing the relationship as shown in Tables 2 to 4 described in Examples 1 to 3 can also be stored and held in the storage medium of the process cartridge. As a result, even if the design of the process cartridge is changed, the same control as in the above-described embodiment can be performed without requiring a change on the device main body side. Also in this case, these information read from the storage medium of the process cartridge may be temporarily stored in the main body storage unit and used.

Further, in the above-described embodiment, the device main body is provided with an operation display unit having functions of an input means and a display means, but these means are, for example, a device (personal computer or the like) connected to the device main body so as to be communicable. You may use the one provided in.

Further, in the above-described embodiment, the image forming apparatus is a process cartridge detachable type, but the present invention is not limited to this, and the cleaning member and the photoconductor may be individually replaceable. In general, a process cartridge is a photoconductor, and at least one of a charging means, a developing means, and a cleaning means as a process means acting on the photoconductor is integrally formed into a cartridge so that it can be attached to and detached from the main body of the apparatus. Is.

Further, in the above-described embodiment, the case where the contact pressure of the cleaning member with respect to the photoconductor differs due to manufacturing variations and the like has been described as an example, but the present invention is not limited to this. For example, the present invention is applied even when the contact pressure setting is intentionally different due to any reason such as a change in the setting due to a difference in the model of the device or a change in the setting depending on the usage environment or usage condition of the device by the user. it can.

Further, the present invention works particularly preferably when the cleaning member is a blade-shaped member, but the cleaning member is not limited to the blade-shaped member. For example, when a cleaning member such as a block-shaped (pad-shaped) one that lacks a difference in contact pressure with respect to the photoconductor and affects the degree of occurrence of defects such as curling and abnormal noise, the present invention is applied. Therefore, the same effect as described above can be expected.

Further, in the above-described embodiment, it is determined whether or not to execute the supply operation according to the environment in which the image forming apparatus is installed, but the supply operation may be executed regardless of the environment.

Further, in the above-described embodiment, the image forming apparatus is a monochromatic image forming apparatus, but the present invention can also be applied to a color image forming apparatus capable of forming a full-color image. For example, FIG. 11 is a schematic cross-sectional view of an example of a tandem type color image forming apparatus adopting an intermediate transfer method. In FIG. 11, elements having the same or corresponding functions or configurations as those of the above-described embodiment are designated by the same reference numerals. Further, Y, M, C, and K are added to the end of the symbols of the elements having the same or corresponding functions or configurations provided for each of the yellow, magenta, cyan, and black colors.

The image forming apparatus 100 of FIG. 11 has four image forming portions S each including a photosensitive drum 1 as a first image carrier, and an intermediate transfer belt 301 as a second image carrier. .. The intermediate transfer belt 301 is an example of an intermediate transfer body that conveys a toner image primaryly transferred from the photosensitive drum 1 for secondary transfer to the recording material P. The toner image formed on the photosensitive drum 1 of each image forming unit S is primarily transferred to the intermediate transfer belt 301 by the action of each primary transfer roller 22 in each primary transfer unit N1. After that, the toner image on the intermediate transfer belt 301 is secondarily transferred to the recording material P by the secondary transfer roller 302 as the secondary transfer means in the secondary transfer unit N2. The toner remaining on the intermediate transfer belt 301 after the secondary transfer step is removed from the intermediate transfer belt 301 by the belt cleaning device 303 as the intermediate transfer body cleaning means and recovered. The belt cleaning device 303 has a blade 304 as a cleaning member that is brought into contact with the intermediate transfer belt 301 so as to be in the counter direction with respect to the moving direction of the intermediate transfer belt 301.

In such an image forming apparatus 100, the present invention can be applied to a blade 3a for cleaning each photosensitive drum 1. Further, the present invention can be applied to the blade 304 for cleaning the intermediate transfer belt 301. In this case, the toner band formed in at least one of the plurality of photosensitive drums 1 is transferred to the intermediate transfer belt 301 and passed through the secondary transfer portion N2 to allow the blade 304 and the intermediate transfer belt 301 to come into contact with each other. Can supply toner in the toner band. When the toner band passes through the secondary transfer section N2, the voltage applied to the secondary transfer roller 302 is set to OFF or a voltage having the same polarity as the normal charging polarity of the toner, or the secondary transfer roller 302 is placed in the middle. It can be separated from the transfer belt 301. In such an image forming apparatus 100, for example, a unit (intermediate transfer belt unit) including an intermediate transfer belt 301 and a belt cleaning device 303 may be attached to and detachable from the apparatus main body 150. Therefore, the pressure distribution information can be held in a sticker attached to the unit or a storage medium provided in the unit. Of course, other methods of presenting the pressure distribution information described above can also be adopted.

1 Photosensitive drum (image carrier)
4 Cleaning device 3a Cleaning blade (cleaning member)
11 Seal (description part)
22 Transfer roller (transfer means)
103 CPU (control unit)
109 IC tag (storage medium)

Claims (8)

In the image forming apparatus
A unit that can be detachably attached to the main body of the image forming apparatus.
An image carrier that supports a toner image and
A cleaning blade that comes into contact with the image carrier at the cleaning unit and removes deposits on the image carrier as the image carrier moves.
Information about the contact pressure of the cleaning blade with respect to the image carrier in each of the plurality of regions of the cleaning blade in the width direction orthogonal to the moving direction of the image carrier, measured in the unit assembly step. An information holding member that holds contact pressure information, and
With a unit equipped with
A transfer member that transfers the toner image from the image carrier to the transfer target, and
An input unit into which the contact pressure information is input and
For each predetermined number of image forming operations, toner is supplied to the cleaning unit using the supply toner image formed on the image carrier during a period other than the period during which the toner image is formed on the image carrier. The execution unit that executes the supply operation and
Have,
In the execution unit, the amount of toner supplied to the region where the contact pressure is the first contact pressure is the first supply amount based on the contact pressure information input to the input unit. The amount of toner supplied to the region, which is the second contact pressure at which the contact pressure is larger than the first contact pressure, is a second supply amount that is larger than the first supply amount. An image forming apparatus characterized in that the amount of toner supplied to each of the regions is set in the supply operation. The image forming apparatus according to claim 1 , wherein the executing unit sets the toner amount by changing the length of the supply toner image in the moving direction. The image forming apparatus according to claim 1 , wherein the executing unit sets the amount of toner by changing the amount of toner per unit area of the image of toner for supply. The image forming apparatus according to claim 1 , wherein the executing unit sets the amount of toner by changing the number of times of supplying toner per a predetermined number of image forming operations. The information holding member is a description unit in which the contact pressure information is described.
The image forming apparatus according to any one of claims 1 to 4 , wherein the contact pressure information is input to the input unit by an operation of an operator. The information holding member is a storage medium in which the contact pressure information is stored.
The image forming apparatus according to any one of claims 1 to 4 , wherein the contact pressure information read from the storage medium is input to the input unit. The image forming apparatus according to any one of claims 1 to 6 , wherein the image carrier is a photosensitive drum. The image forming apparatus according to any one of claims 1 to 7 , wherein the cleaning blade abuts on the image carrier so as to be in a counter direction with respect to the moving direction of the image carrier. ..

Images